Drying Process for Linear Alpha Olefins

Abstract

The present invention relates to a method for preparing linear alpha-olefins by oligomerisation of ethylene, comprising the steps of: (i) oligomerising ethylene in a reactor in the presence of a solvent and a catalyst; (ii) transferring a liquid organic outlet stream of the reactor, containing solvent, catalyst, dissolved ethylene and linear alpha-olefins, to a catalyst deactivation section; (iii) deactivating the catalyst by washing the outlet stream with an aqueous basic phase to obtain a deactivated catalyst containing aqueous phase and a water saturated organic phase; (iv) separating the aqueous phase and the organic phase from step (iii); (v) transferring the water saturated organic phase to a distillation column; (vi) distilling the water saturated organic phase; and (vii) separating the distilled organic and aqueous phases.

1 . A method for preparing linear alpha-olefins by oligomerization of ethylene, comprising the steps of:
 (i) oligomerising ethylene to linear alpha-olefins in a reactor in the presence of an organic solvent and a catalyst;   (ii) transferring a liquid organic outlet stream of the reactor, containing solvent, catalyst, dissolved ethylene and linear alpha-olefins, to a catalyst deactivation section;   (iii) deactivating the catalyst by washing the outlet stream with a basic aqueous solution;   (iv) separating the washed outlet stream from step (iii) into an aqueous phase comprised of deactivated catalyst and a water saturated organic phase comprised of organic solvent, linear alpha-olefin and dissolved ethylene;   (v) transferring the water saturated organic phase to a distillation column;   (vi) distilling the water saturated organic phase to yield a distillation overhead product containing most of the water in the water saturated organic phase and a distillation bottoms product containing most of the organics; and   (vii) separating the distillation overhead product to recover additional water.   
   
   
       2 . A method according to  claim 1 , wherein the separation in step (iv) and/or (vii) takes place in a phase separator. 
   
   
       3 . A method according to  claim 1 , wherein after step (vi) the distillation bottoms product is passed through an adsorber. 
   
   
       4 . A method according to  claim 3 , wherein the adsorber comprised of zeolite, molecular sieve, alumina, silica, or mixtures thereof. 
   
   
       5 . A method according to  claim 1 , wherein the basic aqueous solution comprises alkali metal hydroxide, NH 3 , organic amines or mixtures thereof. 
   
   
       6 . A method according to  claim 1 , wherein the water saturated organic phase is additionally washed with water. 
   
   
       7 . A method according to  claim 1 , wherein the aqueous phase obtained in step (iv) and/or the water obtained in step (vii) are recycled. 
   
   
       8 . The method according to  claim 2 , wherein after step (vi) the distillation bottoms product is passed through an adsorber comprised of zeolite, molecular sieve, alumina, silica, or mixtures thereof. 
   
   
       9 . The method according to  claim 5 , wherein the basic aqueous solution comprises NaOH or KOH. 
   
   
       10 . The method according to  claim 4 , wherein the basic aqueous solution comprises alkali metal hydroxide, NH 3 , organic amines or mixtures thereof. 
   
   
       11 . The method according to  claim 10 , wherein the water saturated organic phase is additionally washed with water. 
   
   
       12 . The method according to  claim 10 , wherein the aqueous phase obtained in step (iv) and/or the water obtained in step (vii) are recycled.